RALEIGH, North Carolina (AP) — A federal grand jury has indicted two-time presidential candidate John Edwards over massive sums of money spent to keep his mistress in hiding during the peak of his 2008 campaign for the White House.

The case of USA v. Johnny Reid Edwards contains six counts, including conspiracy, four counts of illegal campaign contributions and one count of false statements. The indictment was returned in the Middle District of North Carolina Friday.

An Edwards spokeswoman said she wasn't aware of the filing and declined immediate comment.

The indictment is the culmination of a federal investigation that lasted more than two years and scoured through virtually every corner of Edwards' political career.

The investigation has centered on allegations that donations to Edwards were used to support Rielle Hunter, his former mistress and mother of his now-3-year-old daughter. The key questions in the case are whether payments to Hunter and to a campaign staffer, Andrew Young, were intended to keep Edwards' 2008 presidential campaign alive, and whether Edwards knew about those payments.

Prosecutors say the money was essentially campaign spending — intended to save the campaign by keeping Edwards' affair with Hunter secret — and thus an illegal use of campaign funds. They will point out that one donor, the late Fred Baron, was a key figure in Edwards' national campaigns. The other donor was multimillionaire Rachel "Bunny" Mellon.

Edwards' lawyers, on the other hand, say that the money was intended merely to conceal the affair from Edwards' late wife, Elizabeth, and was not connected to the campaign. As such, they argue, the payments were not illegal.

A South Carolina native, Edwards lives in Orange County, N.C. His wife died of cancer last December.